The Build – Part 1
The B44.3 uses 3 gear differentials; one in the front, one in the center and one in the rear. All 3 of these are fluid-filled and can be tuned to make the B44.3 handle however you want on almost any surface.
While they are pretty easy to build, there were a few instances where I had to deviate from the manual to make things fit. So, without further ado, here we go…
Build Notes:
First off, we’ll be working with black grease and differential fluid. Yes, you will spill some and yes, you will get some on your fingers. It’s a good idea to have some rags handy for clean up (Wet Wipes might be good as well).
The instructions call for four #9888 shims on the outdrives; 2 outside the diff and 2 inside. If you do use four, you’ll never get the roll pin through the outdrive. You can use three shims, but make sure you use ONE outside and TWO inside. This will keep the internal sun gear spaced correctly and allow the diff to function properly. The manual actually says you can adjust shims for the best fit, but do you really want to build the entire diff only to find out it’s wrong? This worked for me.
The first thing we want to do is make sure that you have a nice, clean space to work on. I’ll be using one of CowRC’s cool magnetic pit mats. This mat is huge and has foam-lined compartments, allowing me to put separate all the parts for a specific build step. The best part is, of course, the magentic backing so I won’t be dropping any more screws on the ground. I do that alot. Before we start building, I’m going to prep all the outdrives. Slide the small red o-ring over the outdrive and seat it in the first groove. It should just drop into place. Next, slide one shim (yes, one, even though the manual states two) all the way over the outdrive followed by one larger red o-ring. Go ahead and prep all six outdrives. Apply some black grease to the both o-rings as shown and slowly slide the outdrive assembly into the metal differential gear. Don’t be afraid to use too much grease; it only helps coat the o-rings and seal the diff. Wipe away any spare grease once assembled. Build two of these. Follow the same procedure as you did in Step 3 but this time insert it into the diff housing. Build 2 of these. Stand the outdrive side up that has the metal gear and slide 2 of the #9888 shims onto the outdrive. Do this on both assemblies. We’re going to add two of the #9888 shims onto the diff housing side as well. To make things a little easier, I usually slide any shims on a hex wrench and then place the tip on the outdrive. When I release the shims, the fall right into place. Slide the 2x9mm roll pin into the hole in the outdrive and key a sun gear to the pin. I usually use a dab of black grease to keep the gear in place. Do this on all four diff assemblies. Build four of these smaller sun gear assemblies; each shaft should have two sun gears (facing each other) and two small shims. Key one sun gear assembly to the diff housing as shown, making sure the notch in the shaft is facing up. Then do the same thing with then second sun gear assembly, making sure the notch in the shaft is facing down. As you can see, the notches line up and key together. Build two of these. Take the 5000wt diff fluid and pour it into the diff housing. Let it set for a few seconds so the fluid can sink into all the nooks and crannies, then add a little more. You want to put just enough to cover the sun gears; don’t go over this or you’ll have a mess during the rest of the assembly. Set the diff gasket in place, lining up the round holes in the gasket to the mounting holes in the assembly. You can use a very small dab of black grease to keep it the gasket in place. Now take the gasket-side diff assembly and slowly mate it to the diff housing side. Make sure you line up the mounting holes on both assemblies. Press together and, while holding the to halves tightly together, rotate an outdrive to make sure the gears have seated correctly. Now assemble with the four 2.5x10mm screws. Retest your diff to make sure all is rotating smoothly. Assemble both diffs. The final step in the front and rear diffs is to add three shims and a 3/8″ bearing to both sides of the diff. The shim count might vary on your car but we won’t know this until we put the diff assembly in the diff housing. The center diff is much like the front/rear ones. Apply grease to the o-rings on the outdrive and insert into the housing. Add TWO more #9888 shims followed by the large sun gear. Build your smaller sun gear assemblies and, following the same procedure as we used in Step 9, insert the sun gear assemblies into the diff housing. Attach the diff gasket and fill with fluid. Screw the two halves together using the same procedure as in Step 12. Flip the center diff assembly over and attach the spur gear to it.Simple as that, we have all three differentials completed! Set them aside and let’s get rocking on the next part of the build.
Team Associated B44.3 Buggy Build – Part 1 – Differentials
Team Associated B44.3 Buggy Build – Part 2 – Gearboxes
Team Associated B44.3 Buggy Build – Part 3 – Steering
Team Associated B44.3 Buggy Build – Part 4 – Suspension
Team Associated B44.3 Buggy Build – Part 5 – Center Bulkhead
Team Associated B44.3 Buggy Build – Part 6 – Top Decks
Team Associated B44.3 Buggy Build – Part 7 – Turnbuckles / Driveline
Team Associated B44.3 Buggy Build – Part 8 – Anti-Roll Bars
Team Associated B44.3 Buggy Build – Part 9 – Shocks
Team Associated B44.3 Buggy Build – Part 10 – Electronics
Team Associated B44.3 Buggy Build – Part 11 – Wheels, Tires and Body